The dielectric properties of the liquid crystallline polymethacylates with side chain containing a terminal alkyloxy chain have been over wide ranges of frequency and temperature. The temperatures corresponding to the peak of the dielectric loss tangent for PM6BP and PM6BP5 in its temperature dependence agreed well with those phase transition. The activation energies at low temperature agreed with Δ-relaxation which is ε-relaxation by rotation of mesogenic gruop around the backbone chain. The dipole moment have been calculated by using the Frohlich modification of Onsager's equation. The alignment of both materials in the present of an a.c. electric field are also discussed.